This invention relates to the fiber optics splice enclosure art.
Currently, fiber optic cables are in wide use in telecommunications and data communications because of the high volume and high rate at which data can be transmitted over such cables. Many systems previously using conventional electrically conductive cabling have been or are being converted into fiber optic cables. Increased use of fiber optic cables has presented new problems requiring new solutions to be devised to accommodate the characteristics of fiber optic cables.
It is common to install a multi-carrier fiber primary cable to provide telecommunications service to a predetermined area. The primary cable, consisting of perhaps approximately 100 individual carrier fibers, is installed. At specific points along the cable, connections must be made to direct individual service fibers to the end users. Primary cables are typically very long continuous cables and therefore cannot be manufactured with the specific service fiber length at the specific breakoff points. In this situation, it becomes necessary to extract specific carrier fibers from the primary cable and to splice the carrier fiber with service fibers which are routed to the end user location.
Routing and splicing of fiber optic cables as described above is constrained by certain physical limitations of the fiber optic material. For example, one limitation is that fiber optic cables cannot be bent beyond a predetermined minimum radius. Over-bending of the fiber optic cables may kink, crack or break the cable thus interfering with light propagation in the cable thereby impairing the transmission capabilities of the cable. Fiber optic cables also have special splicing requirements for joining two pieces of cable to assure proper propagation of light transmitted through the joined area. As with other data transmission mediums, when the need arises to connect cables it is desirable to permit the connections to be made quickly and easily.
Additionally, it is important to provide a protected environment for the connections between the carrier fibers and the service fibers to assure high quality data transmission. When the carrier and service fibers are weld spliced it is important to assure that the connection is properly retained and will not be exposed to damaging stresses. When mechanical connectors are used to join the carrier and service fibers, it is important to assure that the connections be protected from detrimental environmental effects. Moisture, dust and dirt as well as protective sealants may accumulate between the mechanical connections and thereby impair data transmission.
Prior art fiber optic cable enclosures for the most part are modified variations of electrical splice casings. In electrical enclosures wires may be bent at a very tight radius and the wires are usually fastened with screws or similar fasteners directly to a terminal member. As such, these casings often do not provide sufficient space to accommodate fiber optic cable radius requirements and do not provide means for securely retaining a fiber optic connection therein. Further, prior art fiber optic splice cases are difficult to access and are difficult to seal requiring tapes and/or grease type sealants. As an additional problem, with the prior art fiber optic splice enclosures, often such enclosures are mounted in such a way that access by field personnel is very difficult.